6Noack W E, Schulz P, Tuller F N. Process for the production of ether carboxylic acids and salts thereof [P]. US 5463114. 1995
7Fetceschim G. Mild surfactants and application [J]. J Soc Cosmetic chemists, 1994,15 : 215-217
8Thomas A C. Process for making alkylethoxy carboxylates [P]. us 5233087. 1993
9Kofi O A. Liquid or gel dishwashing detergent containing alkyl ethoxy carboxylate divalentions and alkyl polyethoxy polycarboxylate[P]. US 5739092. 1998